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17 January 2003 AGE-NC Project 02-0946 Page 3 of 9 • November 2002 - Two USTs (UST-I and UST-2) were discovered during excavation of debris and hydrocarbon-impacted soil. The two USTs were single-walled and appeared to be constructed of redwood with steel banding; the tanks were contained in separate brick vaults with concrete floors. Each tank had an approximate capacity of 15,000 to 20,000 gallons. Upon discovery of the tanks, the San Joaquin County Environmental Health Department (EHD) was notified and the tanks were removed under permit. Based on analytical results of soil samples collected from beneath the tanks, it appears that the tanks contained diesel. Details of the UST removal are presented below. 2.3. UST REMOVAL On 26 and 27 November 2002, UST-1 and UST-2 were decommissioned by Mr_ Jim Cornell of Valued Engineering. Prior to excavation of the tanks, soil and debris were removed from the open top of each tank using an excavator and stockpiled on-site pending dispoasl. In addition, approximately 200 gallons of liquid was pumped from UST-2 prior to removal. Following removal of debris,the tanks,brick and mortor vaults and concrete flooring were removed using an excavator and stockpiled on site. The soil beneath the flooring was stained and a strong hydrocarbon-like odor was noted. 2.3.1 Soil Sample Analysis Six soil samples were collected from beneath UST-1, five soil samples was collected from beaneath UST-2 and one soil sample(four-point composite) was collected from the UST-I stockpile; all soil sample locations were approved by the HHD. Soil sampling locations are illustrated on Figure 3.The soil samples were collected in pre-cleaned 2-inch by 6-inch brass sleeves. The ends of each brass sleeve were covered with Teflon sheets,capped and sealed with tape.The samples were then labeled, stored on ice and transported under chain-of-custody to Cal Tech Environmental Laboratories (CTEL),a California Department of Health Services-certified laboratory.The samples were analyzed for: • TPH-g, TPH-d and TPH-mo in accordance with EPA Method 8015M; • BTEX and the fuel oxygenates di-isopropyl ether(DIPE), ethyl tertiary-butyl ether(ETBE), MTBE,tertiary-amyl methyl ether(TAME),tertiary butanol(TBA)in accordance w ith EPA Method 8260B; • 1,2-dibromoethane (EDB) and 1,2-dichloroethane (1,2-DCA) in accordance with EPA Method 8260B; and Advanced GeoEnviranmental,Inc.